skin surface areas that are supplied by a single spinal nerve; surfacte of body can be mapped according to which spinal nerve innervates that part of the body

neuritis

inflammation of the nerves

seiatica

inflammation of the spinal nerve branch in the thigh called the scieatic nerve (longest nerve in the body)

neuralgia

nerve pain

trigeminal neuralgia

compression of the fifth cranial nerve (tic douloureux); has three branches and can result in pain of different areas

bell's palsy

compression, degeneration, or infection of the seventh cranial nerve (facial)

herpes zoster (shingles)

affects skin of only one dermatome, same virus as chicken pox, if immune system is weakened virus will travel out of ganglion and make rash

cerebrospinal fluid (CSF)

clear, colorless fluid that bathes entire surface of CNS, contained within a system of fluid filled cavities called ventricles; for protection (gives cushioning), buoyancy (entire brain immersed in fluid), and excretion (flows one way from ventricles to bloode, removing metabolic waste), endocrine medium (transports hormones); produced mostly in lateral ventricles in choroid plexus

when the flow of CSF is obstructed in any way and the fluid accumulates in the ventricles inside the brain, causing it to swell; compression of surrounding tussue causes brain tumor, meningitis (infection of meninges), prematurity (blood vessels can burst easily)

spinal tap (spinal puncture)

sample of CSF fluid can be obtained from spinal cavity in lumbar region; can be examined for infections